Sigh. Why do people talk as if retailers get 100% of the difference between the cost price and sale price of an item to keep as profit?
Once you've paid a supplier for the item, you have to pay a company to ship it to you at your warehouse or distribution centre from wherever - e.g. China or Spain to the UK. You have to pay someone to unload and shelve it. You pay for the storage space while it's waiting to be sold. When it is sold, you pay 20% VAT, you pay someone to package it and for the despatch materials, and in most cases now the company pays to ship the item to the customer. This means you also need staff to process returns.
On top of this, you're paying for someone to photograph and style the item for the site, someone to write the copy, someone to maintain the website (in and/or out of house), advertising/marketing, merchandisers and buyers, a finance team, card fees to Visa/Mastercard, and that's all only for mail order - there are store costs instead of the shipping fees if you buy on the high street, and customer service staff to pay for online.
It is not a "scam". If retailers weren't making anything after paying all of that, what's the point?